Gates wouldn't go back and change the past, but he is in favor of Microsoft-built tablets in the future.

"I actually believe you can have the best of both worlds. You can have a rich eco-system of manufacturers and you can have a few signature devices that show off, wow, what's the difference between a tablet and a PC?"

Not only that, but he thinks Windows 8 tablets, including the Surface, will replace the traditional PC.

"You can get everything you like about a tablet, everything you like a PC, all in one device. That should change the way people look at things."